Pulmonary diseases are on the rise today due to the extensive iatrogenic pollution in our world. Unless a global commitment is undertaken to control pollution, the incidence of pulmonary diseases will be on the rise.
The essential feature is widespread inflammation of the airways. This is in response to a multiplicity of stimuli: drug-related, allergic, environmental, occupational, infectious, food-related, exercise-related and emotional.
A variety of drugs like aspirin, beta blockers (as beta stimulation dilates airways) like those used to control hypertension, some colouring agents, an assortment of food products like sea food, salads and fresh fruit contain preservatives and other chemicals that cause wheezing. Environmental airborne factors irritate the lining at any time of the day. Smoking is one of the principal irritants.
During intense aerobic exercise, a person often breathes through the mouth and the humidification of the inhaled air by the nasal passages and the sinuses is lost. This results in thermal cooling of the air that reaches the distal airways, causing wheezing. Occupational factors like exposure to strong smells, leather, cotton, etc., are all well-known agents that provoke wheezing. Virtually any agent can cause wheezing. Infections cause wheezing and this is due more to viruses than to bacteria. Emotional stress increases the parasympathetic tone and provokes wheezing.
The mechanism by which the spasms are triggered is not fully understood, but there is an antigen antibody complex which releases the chemical mediators of inflammation and hypersensitivity, bypassing the cellular defense mechanisms. Such chemicals include histamines, prostaglandins and a variety of other substances. This allergic response is mediated by T and B lymphocytes. The hallmark is reduction in airways diameter due to oedema, mucus plugs, and smooth muscle constriction. Air trapping occurs. Hypoxia is a universal finding during acute attacks. There is carbon dioxide retention and metabolic acidosis results.
The disorder can be acute or chronic. An acute exacerbation of a chronic condition is also possible. The symptoms consist of cough, wheezing and breathlessness (dyspnoea). They can be present singly or in varying combinations. A small amount of sputum, typically sticky, is produced. Ventilatory assistance may be required if the spasms worsen. Occasionally, death supervenes.
No single test is conclusive of asthma; but a clinical conclusion is well assisted by pulmonary function tests. This shows reduction of various parameters. An adult can, for the first time, suffer the problem in middle age — the so-called adult onset asthma. Hence it is good to practise yoga to keep oneself fit all the time.
The treatment consists of oral drugs or the use of different systems of inhalers which deliver the drug by a fine mist into the airways. The oral drugs stimulate the beta receptors in the lining of the bronchial tree. They dilate the airways by chemical changes through the sympathetic nervous system. Since the sympathetic tone is reduced in asthma, drugs that provoke this system are necessary. Drugs like the methylxanthines (theophylline) produce dilatation through certain chemical mediators. Salbutamol is a drug that works along the sympathetic nervous system, stimulating the beta receptors. Cromolyn sodium prevents the mast cells from releasing the chemicals of an allergic reaction. It is preventive, not curative, in action. Newer drugs which provide quicker relief are available now, but none is natural in its mode of action. At the end of the drug list are steroids which reduce airway blockage by their anti-inflammatory action. Intravenous therapy is used, depending on the clinical condition.
Most of the drugs have side effects like tremors, palpitations, sweating, ectopic beats and gastric disturbances. This is related to the severity of the disease and, therefore, the frequency of drug usage. It is not possible to predict whether the disease will worsen or not, as the aggravating conditions are multifactorial. Moreover, if the patient is in a state of tense anticipation of an attack, it is difficult to reduce the dosage. Regardless of the pattern of attacks, an asthmatic must be taught how to relax the mind. Asthma is described as psycho-somatic as the mind is linked to the respiratory tree, and stress upsets its delicate chemical balance.
The tremors are due to over stimulation of the sympathetic system through the beta receptors. The gastric irritation is due to a direct effect on the lining of the stomach. The incidence of side effects also depends on the individual susceptibility of the patient to the drug. However, the usefulness of drugs in dealing with a problem like asthma cannot be understated.
Though an asthmatic can never be completely free of the disease, it is possible to strengthen the system by the addition of the parameter of yoga to the regimen of treatment. In some cases, the practice of yoga should be continued along with medication for many months. In others, it may be possible to discontinue medication in a short while. If an asthmatic is able to ensure stability with minimum dosage of the drug aided in the greater part by the practice of yoga, it is certainly an achievement in today's polluted world. Many asthmatics feel better if they change their place of living. This may be migration to a different climate in the same or a different country. So long as they live in a different place, their attacks are highly infrequent. For example, when an Indian asthmatic goes to reside in the West, the attacks reduce and almost disappear. When they return to India, the moment they alight from the aircraft, the spasms begin due to the high humidity and pollution in some states.
Yoga is very useful in the treatment of asthma as it primarily works by stabilising the autonomous nervous systems. According to yoga, quietude in the body always stabilises irritable responses. The parasympathetic tone is in excess in asthma; exercises always help balance the autonomic tone by raising the sympathetic. It is possible to change the very responsiveness of the body. It is a matter of training. Asanas do their part by helping to ease the congestion in the lungs. This promotes relaxation of smooth muscle and better oxygenation. The change, however, does not happen overnight, as asthma is a chronic disorder and irritable responses take time to stabilise. The earlier the asthmatic begins yoga the better the response. Constant practice is required to change the sensitivity of the body.
The practice of asanas during an attack is different from when the patient is free of symptoms. All asanas are useful. If the patient is stable, standing poses can be practised. Back bends are very helpful to open the frontal lungs and relax the bronchial muscle. Props may be needed. Immediate improvement in oxygenation occurs. The cells lining the bronchial tree are soothed by the improved blood flow and breathing mechanics of back bends. The sympathetic system being stimulated, the bronchi dilate. Constrictive activity is reduced with the lowered parasympathetic tone. During acute attacks such poses cannot be done by some patients. For such people forward bends are helpful.
Forward bends are useful during an attack, but the requirement varies from person to person. The posterior lungs are made to open out or supported and rested, the secretions squeezed out and the nervous tone altered, relieving the stress on the lungs. Inverted poses condition the lungs for exertion of a particular kind. They flush the lungs free of accumulated toxins and enhance fresh blood flow, healing the irritated areas. The circulation of the bronchial tree has to be soothed and refreshed to prevent an allergic response. Props are usually needed.
Role of Pranayama
Pranayama is of direct help in this situation. The sympathetic tone is raised and vagal tone lessened; in other words, a balance is obtained. The effect can be felt soon after the practice of pranayama is over. A single long inhalation has been shown to enhance airways relaxation. The resistance to air flow in asthma occurs in medium sized airways. The slower and longer the inhalation, the better the relaxation. The exhalation in yoga is never forced as it would narrow the bronchi. It is rather a slow, very deliberate process. It can take as much as one minute to complete an inhalation and exhalation.
The normal respiratory rate is 16 to 17 per minute. In pranayamic practice this is brought to one or two per minute. One can well imagine the relaxation of the bronchial tree. Regular practice improves ventila-tion, better control of smooth muscle as the process of breathing helps in voluntary opening of airways. There is a gradual change in the frequency of attacks and then a reduction in their severity. The breathing soothes the lining of the bronchial tree and prevents hypersensitivity to external allergens. Hence the chemical irritation of the lining is less. In pranayama, the varying rates of inhalation and exhalation give added benefits. As pranayama works at the microcellular level, stabilisation occurs over a prolonged period of time.
All asthmatics cannot start with pranayama. When they are breathless most of the time, how can they practise pranayama which demands slow breathing? First, the lungs need to be rested before breathing is done. Some need to practise asanas to stabilise the lungs and relieve the strain, before pranayamic practice can be initiated. Pranayama is done lying down on pillows to promote deep breathing. Simple ujjayi breathing may be used at first; and, as the condition improves, strenuous pranayamic techniques which have better effects can be taught.
If pranayama is practised regularly the patient will most certainly feel a marked difference. Nevertheless, spasms may continue to occur and the patient should never stop practice in despair but persevere. Drugs may still be needed, but the patient will do better with yoga and medication than with medication alone. In some cases, yoga alone will suffice. As the disorder is one of a hypersensitive nature, relapses are common. Yet, in the long run, stabilisation does occur. Many so-called yoga camps conducted for asthma wrongly claim relief or cures in a short period. Asthma, being a chronic disorder, requires many years for stabilisation, not to speak of a total cure.
Resting poses like supta virasana, setu bandha sarvangasana, half halasana, viparita karani and viparita dandasana are the asanas recommended in the treatment of asthma. During an attack, the use of back or forward bends depends on the patient's needs. All the asanas are done on props to help avoid strain and not provoke wheezing. As the condition improves, props can be dispensed with.